Considerations: https://technet.microsoft.com/en-us/library/cc770334(WS.10).aspx
Tuning Search for RDS: http://www.peters.com/tuning-search-service-remote-desktop-services-server/
Issues: http://www.brighthub.com/computing/windows-platform/articles/99129.aspx
Optimize: http://www.brighthub.com/computing/windows-platform/articles/21057.aspx
Disabled by Default: https://support.microsoft.com/en-us/help/3204979/windows-search-is-disabled-by-default-in-windows-server-2016